• 한국콘텐츠학회논문지
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• 제13권3호
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• pp.9-21
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• 2013

GPU의 연산 능력과 유연성이 강화됨에 따라, GPU는 그래픽 응용프로그램뿐만 아니라 범용 응용프로그램도 수행한다. 특히, GPU 회사들이 제공하는 API를 활용함으로써 프로그래머들은 보다 쉽게 GPGPU 응용프로그램을 작성할 수 있다. 하지만 대부분의 범용 응용프로그램은 분기 명령어를 많이 포함하고 있기 때문에, 범용 응용프로그램을 수행하는 경우 GPU의 연산 자원을 충분히 활용할 수 없다. 분기 명령어를 처리하기 위해서 다양한 워프 생성 기법들이 제안되었다. GPU 구조에서는 높은 연산 자원 활용률을 보이는 워프 생성기법이 우수한 성능을 보일 것으로 예상된다. 하지만 예상과는 달리, 실험 결과에 따르면 높은 연산 자원 활용률을 보이는 워프 생성 기법의 성능이 상대적으로 낮은 연산 자원 활용률을 보이는 워프 생성 기법의 성능보다 낮게 나타난다. 높은 연산 자원 활용률을 보이는 워프 생성 기법에서 유발한 많은 메모리 요구로 인한 심각한 메모리 병목 현상이 원인으로 분석된다. 그러므로 적절한 하드웨어 지원이 없는 경우, 높은 연산자원 활용률이 반드시 우수한 성능을 보장한다고 할 수 없다. 이러한 이유로, 본 논문에서는 하드웨어 자원과 워프 생성 기법사이의 상관관계에 대한 상세한 분석을 수행하고자 한다. 본 논문의 분석 결과는 분기 명령어에 의해 발생된 GPU의 성능 저하 문제를 해결하고자 할 때 중요한 가이드라인이 될 것이다.

• 천문학회보
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• 제39권2호
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• pp.63.1-63.1
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• 2014

The galaxy disk warp is a common phenomenon, yet their properties and formation mechanism(s) are still unclear. Here, we introduce a new automatic measurement method for the warp properties of stellar disks in nearby edge-on galaxies, including warp's angle, shape, and asymmetry. We obtain isophotal maps of edge-on galaxies and express each of isophote contours in polar coordinates (${\Phi}$, R) centered on the galaxy centers. Two peaks in the ${\Phi}$-R diagram correspond to the outermost tips of each isophote. The locations of peaks, in turn, inform us of the misalignment between their inner and outer galactic planes, i.e., the warp. We apply this method to SDSS Stripe 82 co-added data and discuss its reliability and validity. Based on the measurement of warp properties, we also investigate their correlations with both intrinsic and environmental properties of warped galaxies.

• 천문학회보
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• 제36권2호
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• pp.58.1-58.1
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• 2011

We present our N-body simulation study on the disk galaxy warp formation via close encounters. Using a publicly available code Gadget2, we investigate morphological and kinematical structures of disk galaxies while the galaxies are undergoing fly-by encounters with adjacent dark matter halos. In this study, we find that warps can be excited by impulsive encounters and sustained for a few billion years. Most of the warps from the simulation show inclination angles that are comparable to the observations. The creation of warps, their inclination and their lifetimes are governed primarily by the following three parameters: the impact parameter (the minimum distance between two halos), the mass ratio between two galaxies, and the incoming angle of the intruder. We discuss pros and cons about our alternative scenario in comparison with existing explanations.

• 천문학회지
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• 제40권1호
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• pp.9-16
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• 2007

We examine the morphology and luminosity distribution of a strongly warped spiral galaxy PGC 20348 by conducting a detailed BVI CCD surface photometry using BOAO 1.8m telescope. The radial surface brightness shows a break at warp radius $(r_{\omega})$ with a shallow gradient in the inner disk and a steeper gradient in the outer disk. The luminosity of east side of the disk is ${\sim}0.5$ mag fainter than the west side at r > $r_{\omega}$. The reason for the asymmetric luminosity distribution is thought to be the asymmetric flarings that result in the formation of a large diffuse region at the edge of the east disk and a smaller diffuse region at the west disk. The vertical luminosity profiles show a thick disk component whose scale heights increase with increasing galactocentric distances. The warp of PGC 20348 seems to be made by the tidal interactions with the two massive companion galaxies since the flarings and radial increase of disk scale heights are thought to be general properties of tidally perturbed disks. According to the colors of the two clumps inside the diffuse region at the edge of the east disk, they seem to be sites of active star formation triggered by tidal forces from the companion galaxies.

• 천문학회지
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• 제49권6호
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• pp.239-253
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• 2016

We determined the warp parameters of 192 warped galaxies which are selected from 340 edge-on galaxies using color images as well as r-band isophotal maps. We derive the local background density (${\Sigma}_n$) to examine the dependence of the warp amplitudes on the galaxy environment. We find a clear trend that strongly warped galaxies are likely to be found in high density regions where tidal interactions are supposed to be frequent. However, the correlation between ${\alpha}_{\omega}$ and ${\Sigma}_n$ is too weak for weakly warped galaxies (${\alpha}_{\omega}$ < $4^{\circ}$) and the cumulative distributions of weakly warped galaxies are not significantly different from those of galaxies with no detectable warps. This suggests that tidal interactions do not play a decisive role in the formation of weak warps.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2008년도 한국우주과학회보 제17권2호
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• pp.30.1-30.1
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• 2008

We investigate the evolution of the initially tilted, self-gravitating disks in a live axisymmetric or triaxial halo. Our study shows how the axisymmetric and triaxiaility of the halo alters the evolution of the warp compared to the spherical case. We attribute the development of warps to the torque between a halo and disk and that between the inner and outer regions of the disk. We discuss if the triaxial halo can be responsible for the formation and maintenance of the warp phenomena even in the presence of dynamical friction between the disk and the halo.

• 복식
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• 제58권3호
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• pp.79-92
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• 2008

The purpose of this study is to develop knitwear design expressed not also Green but also LOHAS using natural yarns(wool and cotton) dyed with various natural sources(sappanwood, indigo plant, turmeric, cochineal, coffee, gallnut, and persimmon juice). This researcher tried to suggest solution scheme through the development of knitwear designs to break from the cottage industry and the limitation of design in Jeju and to preserve of traditional dye with persimmon juice simultaneously. Knitting is the formation of a fabric by the interlooping of one or more sets of yarns with hand knitting or industrial knitting. In hand-knitting, the two fundamental stitches are described as knit depending on the direction of the loop formation, front to back or back to front. In machine-knitting, the direction of loop formation is fixed, unless the stitch is mechanically transferred from front to back needle bed or vice versa. Industrial knitting technology can be divided into two main areas - weft knitting and warp knitting. Each has a different principle of construction. The majority of knitted fabrics for clothing are weft-knitted, and so this study is used weft-knitting and hand knitting technology. To achieve this purpose, researcher tried to present a lot of knitwear designs using yarns dyed with various natural sources focusing on Modern & Sophisticated Image and Elegance & Romantic Image to satisfy adult and missy consumer needs.

• Fibers and Polymers
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• 제6권2호
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• pp.113-120
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• 2005

Helium-oxygen plasma treatments were conducted to modify poly(trimethylene terephthalate) (PIT) and poly(ethylene terephthalate) (PET) warp knitted fabrics under atmospheric pressure. Lubricant and contamination removals by plasma etching effect were examined by weight loss $(\%)$ measurements and scanning electron microscopy (SEM) analysis. Surface oxidation by plasma treatments was revealed by x-ray photoelectron spectroscopy (XPS) analyses, resulting in formation of hydrophilic groups and moisture regain $(\%)$ enhancement. Low-stress mechanical properties (evaluated by Kawabata evaluation system) and bulk properties (air permeability and bust strength) were enhanced by plasma treatment. Increasing interfiber and interyarn frictions might play important roles in enhancing surface property changes by plasma etching effect, and then changing low-stress mechanical properties and bulk properties for both fabrics.

• 복식
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• 제37권
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• pp.149-162
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• 1998

This study is thed Embroidery, Cross-stitchery, Weaving, Wax-Printing of technique and design appeared in textile of Miaos dwells in south-west among the minority people of china. The study is as follows. First, the technique of textile1) satin stitch, couching stitch, french-knot stitch, etc. using anther silk thread or cotton thread color 2) cross-stitchery 3) hand-weaving technique which is shaped other warp or weft using simple loom 4) the technique of dyeing of pattern using effect with wax. These methods are singly used mixing together, therefore doubled beauty. Second, these technuque of ornament have other independence, specially ornament apron, sling, sleeve borders, slack borderss, edge of upper garment, take off and put on easily, heighten effect of various ornament, can preserve many years. Third, Maker, female born in this country fashion by need of herself, used liberal method shown in unique creativity of life. This texture make standards capable female proud of intelligent and skill of herself. Fourth, Design appeared in textile like as pattern flying bird in the sky, strolling beast in the field, lion rolling gem, laughing dragon winding snake at gem, birks, flowers, fish, butterfly is used as the wish of long life, a lucky sign. They expressed creativity and unique conception using formation : the technique transform other shape using by omitting or adding or overestimating. Geometric pattern of tartan, revealing, Fifth, composition structure having balance and symmetry or contradiction towards center and circumstance of the center harmonized repeatedly method, expressed unique artful attraction by full composition.

• 한국의류학회지
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• 제46권2호
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• pp.367-374
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• 2022

Herein, a highly elastic e-textile band with a two-wire transmission line was designed and fabricated for smart clothing applications. A conductive yarn with a very uniform low electrical resistance of 0.0357 Ω/cm was developed and used for the signal and ground lines. To control the elasticity of the e-textile band, spandex yarns were added in the warp direction during knitting and the tension was adjusted. As the length of the e-textile band increased, its RF performance deteriorated. Furthermore, the frequency corresponding to -3 dB S21 was lower in the 30% stretched band than in the unstretched band. For the e-textile bands with lengths 10, 50, and 100 cm, the frequencies corresponding to -3 dB S21 were 107.77, 24.56, and 13.02 MHz when not stretched, and 88.74, 22.02, and 12.60 MHz when stretched by 30%. The fabricated bands were flatter, more flexible, and more elastic than transmission line cables; thus, they can be easily integrated into wearables and smart clothing. However, to increase RF performance and achieve optimum utilization, future studies must focus on the fabrication of transmission lines with lower resistance and reduced distance between the signal and ground lines, and thus the number of transmission lines can be increased.